Conventional automotive restraint systems, including airbag module assemblies, are installed to protect the vehicle occupants in the event of a collision. Airbag module assemblies are installed by automobile manufacturers in multiple locations throughout the cabin of the vehicle, including the steering wheel (known as a driver's airbag or “DAB”), the passenger side dashboard (a passenger airbag or “PAB”), and the side doors. Many airbag modules implement similar components, such as airbags, inflators, ignitors, covers and reaction housings. Typically, these components are assembled within the reaction housing which in turn mates or interlocks with the cover to form an airbag storage volume.
The prior art has resorted to a number of approaches for attaching the cover to the reaction housing, including anchoring the sidewalls of the cover to the reaction housing through the use of rivets, bolts, or brackets. Referring to FIG. 1, an airbag module assembly, referred to generally with the reference numeral 1, utilizing one such conventional cover attachment method, also referred to as the snap-and-hook method, is shown. The airbag module assembly 1 includes a module cover 100 having an upper, typically decorative surface with downwardly extending sidewalls 200. Openings 10a, 10b, 10c, 10d, 10e, 10f and 10g provided in the sidewalls 200 are spaced and aligned from the lower distal ends of the sidewalls 200. As is known in the art, the module cover 100 is typically provided with one or more tear seams (not shown) for providing opening of the module cover 100 upon deployment of an airbag 60.
The airbag module assembly 1 further includes a reaction housing 300 having a base with a central opening through which an upper portion of an inflator 350 projects. The inflator 350 is attached to the reaction housing 300 by fasteners 352, 354, 356 and 358. A folded airbag cushion 60 is then retained on the base of the reaction housing 300 surrounding the inflator 350 by an airbag mounting member (not shown) or retainer ring (not shown) attached to the base as is well known in the art. An electrical connector 90a, 90b is provided for coupling to an inflator 350 which serves to inflate and deploy the airbag cushion 60. The reaction housing 300 includes two brackets 80a, 80b provided for attaching the airbag module assembly 1 to the steering wheel (not shown) of the vehicle.
As shown in FIG. 1, the base of the airbag housing 300 has a plurality of downwardly extending legs 70a, 70b, 70c, 70d, 70e, 70f and 70g each having a U-shaped groove forming a hook-like tabs for lockingly attaching the reaction housing 300 to the sidewalls 200 of the airbag module cover 100. The airbag module cover 100 is attached to the reaction housing 300 by placing the cover over the housing, and inserting the openings 10a, 10b, 10c, 10d, 10e, 10f and log in the sidewalls 200 of the airbag module cover 100 into the corresponding legs 70a, 70b, 70c, 70d, 70e, 70f and 70g on the reaction housing 300. The tabs on the legs 70a, 70b, 70c, 70d, 70e, 70f and 70g are then deformed or biased inwardly into the openings 10a, 10b, 10c, 10d, 10e, 10f and 10g to lockingly attach the sidewalls 200 of the airbag module cover 100 to the reaction housing 300.
One drawback of conventional methods of airbag module cover attachment is that such methods typically require additional steps in the manufacturing process, resulting in production delays due to increased time needed to produce the airbag module assembly. In addition, service of airbag modules utilizing such attachment methods is time consuming and may result in damage to either the cover or the reaction housing during detachment and removal of the rivets, bolts, or snap hooks.
Therefore, there exists a need for an apparatus for attaching a cover to a reaction housing that reduces manufacturing time while remaining simple in design and easily accessible for future service.